This invention relates to product inspection methods and apparatus, and more particularly to methods and apparatus for optically determining whether or not a product has an acceptable appearance.
For many products such as consumer goods like packaged foods, beverages, cleaning products, health and beauty aids, cigarettes, cigars, etc., it is very important that the external appearance of the product or its packaging be uniform and defect-free. Yet these products are typically produced in such large quantities and at such high speeds that some form of automated optical inspection is practically essential. Many prior art optical inspection techniques rely on examining only preselected parts of the object being inspected. It is therefore possible for such prior art systems to miss defects occurring in regions other than those preselected for examination, and/or to miss defects of a kind that were not anticipated when the system was set up. Such prior art systems must also be customized for each product inspection task. This requires a high level of skill and is very time-consuming.
In view of the foregoing, it is an object of this invention to provide optical product inspection methods and apparatus which process an overall image of the product being inspected so that a significant defect or deviation from the norm occurring anywhere in the image will cause the associated product to be identified as deviant or defective.
It is another object of this invention to provide optical product inspection methods and apparatus which are of universal application and which can automatically adapt to each new inspection task without requiring elaborate set-up by a highly skilled operator.
It is still another object of this invention to provide optical product inspection methods and apparatus which can automatically acquire the information required to perform each new inspection task without the intervention of a highly skilled operator.